A network of an operator is usually a multi-layer network. For example, a transport technology such as a Synchronous Digital Hierarchy (SDH), an Optical Transport Network (OTN), and Wavelength Division Multiplexing (WDM) may be used at a lower layer to build a transport network, to bear a packet switched network of a type such as the Internet Protocol (IP) and MPLS at an upper layer.
A multi-layer network may be controlled in a centralized manner. For example, a centralized transport network controller is introduced in a transport network, and the transport network controller implements network topology discovery, path computation, and path creation. In terms of path creation, the transport network controller may use, for example, the OpenFlow protocol to directly deliver a cross-connect creation command to each node through which a path passes. Meanwhile, a centralized routing controller is introduced at an IP/MPLS layer to schedule IP or MPLS streams in a centralized manner. During a link failure or link congestion at the IP or MPLS layer, the routing controller may further drive the transport network controller to create a new transport path, so as to generate a new logical link at the IP or MPLS layer.
To implement the foregoing multi-layer network management, the routing controller and the transport network controller both need to sense information about a cross-layer link in the network and perform control. In addition, the transport network at the lower layer further allows multiple upper-layer IP/MPLS routing domains to provide a transport service. Therefore, the transport network controller further needs to sense a routing domain to which the cross-layer link belongs at one end of an upper layer.
In the prior art, for each cross-layer link, a manual configuration method is used to configure information about the link on a routing controller and a transport network controller, where the information is, for example, identifier information of ports at two ends, and information about a routing domain to which the link belongs. However, because a quantity of cross-layer links is large, implementation is complex and reliability is low.